As superconductive ceramics to which the present invention relates, there are the La-Sr-Cu-O system, Y-Ba-Cu-O system and the like having a high superconductive critical temperature Tc exceeding 40K or 90K. Since these ceramics do not require expensive liquid helium as a refrigerant, and can realize a superconductive state by a relatively simple apparatus, they are expected to be applied to various finds fields as new materials replacing conventional superconductive materials.
(Literature 1: Preprints of the Seventh Research Forum on Electronic Materials, pp. 6-7, Literature 2: G. W. Crabtree et al., Advanced Ceramic Materials, Vol. 2, No. 38, Special Issue (1987), pp. 444-456).